Abstract: A vehicle height adjust control apparatus, incorporating a slope determination apparatus, has a vehicle speed sensor, a vehicle height detector that detects a rear vehicle height of a rear portion of a vehicle body and front vehicle heights at the right and left front wheel positions, and actuators for changing the front and rear vehicle heights. In a case where the detected vehicle speed or an acceleration calculated from the detected vehicle speed is small and where the difference between the detected front vehicle heights at the right and left wheel positions is small and the averaged front vehicle height considerably deviates from a target vehicle height, a microcomputer determines that the vehicle is on a steep slope.